Porsche Panamera S E-Hybrid review

The Porsche Panamera is now available as a plug-in hybrid that can travel more
than 20 miles on electric power

The Porsche Panamera S E-Hybrid is designed to be fast and frugal

By Andrew English

10:31AM BST 31 May 2014

If the idea of a 2.1-ton car that's capable of 167mph and 91mpg strains your credibility, then prepare to be gullibility-extended to the max here. Porsche’s new Panamera S E-Hybrid plug-in ostensibly offers 89 grand’s worth of luxury eco express capable of outlandish fuel economy, tax-efficient environmentalism and super-quick performance. Can all this be true?

A bit of context first. The 2007 Panamera concept was far from the world’s best looking five-door, but Porsche put it into production in 2009, and against expectations it sold in reasonable if not spectacular numbers.

Two years later, seeing a change in the automotive weather, Porsche produced a petrol-electric hybrid version, aimed primarily at the US market. With a 46bhp electric motor that simply augmented the engine’s power and scooped up braking energy, it was heavy and expensive and didn’t qualify for much in UK tax terms.

Now Porsche’s engineers have reinvented the hybrid Panamera as a plug-in model, with a more powerful electric motor and a bigger capacity battery that takes four hours to recharge from a UK household socket. This gives it an electric-only range of 22.4 miles at a maximum speed of 84mph. It’s also eligible for a Government purchase price subsidy of £5,000, is exempt from the London congestion charge and attracts car tax bills of about £150 a month for top-rate tax payers.

Its 91mpg official fuel economy seems barely credible, but the testing of any hybrid is difficult. Some can be driven solely on electrical power, some not. In addition the plug-in hybrid gives a one-time economy boost between recharges, but how to incorporate that into a single fuel consumption figure? The EU plug-in test works as per ordinary cars, but then is weighted with complicated algebra based on two separate power tests. It all seems like dark magic derived from inconceivable driving states, providing figures unattainable by mere mortals. For the record we managed between 23mpg and 67mpg depending on the state of battery charge and the mode selected, while our average was 35mpg.

The plug-in Panamera looks a bit sharper than the standard car, thanks to new headlamps and tweaked rear styling. Our test car sported a deep-gloss claret paint job, which costs an extra £801 and appeared to have been splattered with iridescent lime-green paint in the manner of a Jackson Pollock. This is Porsche’s way of getting down with the eco kids by garishly highlighting brakes and badges.

The interior is large, tautly upholstered in black leather and highlighted with polished aluminium – it’s smart but slightly sinister. The five-dial instrument binnacle is obscured in part by the gear-change paddles and four steering column stalks. There’s no conventional speedometer just a digital read out. The centre console is covered in switches (there are more than 70) so it’s hard to find any single function. The rear seats will accommodate a couple of six-foot adults in reasonable comfort, but the batteries eat into the Panamera’s boot capacity, reducing it by around a quarter and forcing you to pack light for weekends away. Amongst other options, which pushed the price of our test car to over £100,000, were the most spectacularly uncomfortable sports seats, which cost £4,484.

Start the plug-in Panamera and nothing much happens apart from a Dayglo green needle moving to ‘Ready’ in a power/charge meter that could have been borrowed from a steam-punk power station. There are four driving modes: Hybrid, Sport, E-power and E-charge.

E-power is the default setting, giving the maximum electrical range (which we found to be about 13 miles) and adding artificial detents to the throttle action to prevent you from inadvertently starting the engine. When the battery charge level falls low enough, the car switches to Hybrid, using electric drive whenever possible and coasting with the engine off if you lift off the accelerator. Coasting is a quite delightful sensation where you feel as if the wind alone is speeding you to your destination; it makes the sharp lift-off braking characteristics of, say, BMW’s electric i3 seem distinctly crude.

E-charge uses the engine’s spare capacity to charge the battery, which takes about 25 minutes of light cruising. This is a spectacular waste of power and it was in this mode, while making brisk progress, that we saw consumption plummet to 23mpg. This E-charge mode seems to anticipate a future city, which not only mandates electric-only operation of private cars, but can also police such a requirement.

Sport mode is where the petrol engine and the electric motor work together to get the Panamera down the road with the greatest alacrity, and while the engine starting/stopping on the fly is delightfully inaudible and smooth, at high revs the sounds from under the bonnet are industrially vocal.

In addition there’s a sport mode for the suspension, but on our car’s optional 20-inch wheels this was a redundant setting. The Panamera is stiff enough in the optimistically named Comfort mode. Borderline harsh in fact, though body control is pretty good. Unfortunately the car’s 2.1-ton kerb weight adversely affects the ride and leaves it feeling a little reluctant to turn into bends, and while the steering remains precise, that mass has damaged the intimate relationship between driver and car which marks out conventional Panamera models.

The hybrid system has also affected the brakes, leaving the pedal feeling soft and inconsistent, with the amount of force needed varying according to the state of the battery charge. They also clatter the car to a halt as the system greedily scavenges every volt of regeneration.

What should have been a brilliant electrical run around and super tourer combo isn’t quite the sum of its parts, then. This plug-in Porsche is too heavy, which compromises the ride and handling, plus the braking system is badly flawed. What’s more, the Panamera is too expensive for its tax breaks to make much sense, and there’s the question of just how many owners will genuinely plug it in regularly to make the most of its environmental potential. Nice idea chaps, now back to the drawing board.

Verdict: What should have been a delightful combination of battery electric runaround and big powerful tourer is compromised by its weight, price and inconsistent braking performance. Realistic fuel savings are far below those claimed, and how many owners will really charge up the battery?

Verdict: Two out of five stars

RIVALS

Lexus GS 450h Sport, from £51,495

Non plug-in hybrid from the world’s technology leaders. Good looking if not as svelte as the Panamera. Quick though, with its 3.5 litre V6 and electrics giving a top speed limited to 155mph, 0-62mph in 5.9sec, 45.6mpg and 145g/km. Handles well and is comfortable.

Audi A7 3.0 BiTDI Black Edition, from £56,795

A very classy piece of kit, although not that environmentally friendly, with a top speed of 155mph, 0-62mph in 5.3sec, 44.8mpg and 166g/km. Fine driving and well appointed 4x4 cruiser.

BMW 640d Gran Coupe M-Sport, from £69,540

Four-door coupé, with much better packaging than the two door and better looks. Drives beautifully and the interior is lovely, although some options are completely over the top. Top speed is 155mph, 0-62mph in 5.4sec, with 49.6mpg and 149g/km.